新型电极材料Li_5Cr_9Ti_4O_(24)的制备及其性能

Preparation and Performance of New Type Li_5Cr_9Ti_4O_(24) Electrode Material

采用溶胶凝胶法合成一种新型的Li_5Cr_9Ti_4O_(24)钛酸盐材料,用X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、循环伏安(CV)、充放电测试和阻抗测试等方法研究了样品的结构和电化学性能。结果表明,Li_5Cr_9Ti_4O_(24)粒径大小约为100~200 nm,具有同LiCrTiO_4相似的晶格结构;循环伏安曲线表在1.227 V/1.772 V和1.334 V/1.761 V处出现氧化还原峰;在不同倍率下充放电时,Li_5Cr_9Ti_4O_(24)有较好的放电比容量和倍率性能,大倍率充放电曲线表明Li_5Cr_9Ti_4O_(24)材料具有很高的循环稳定性;阻抗图表明循环后的Li_5Cr_9Ti_4O_(24)材料生成SEI膜。

A new titanate material Li5 Cr9 Ti4 024 was prepared by a simple sol-gel method. The structure and electrochemical performance of the materials were investigated by X-ray diffractometry （XRD） , scanning electron microscope （SEM） , cyclic voltammetry （CV） , charge-discharge tests and electro chemical impedance spectroscopy （EIS）. The results show that Li5CrgTi4024 material has similar lattice structure with LiCrTiO4 and the particle size of LisCr9Ti4024 material is about 100--200 nm. Cyclic vohammetry curves indicate that there are reversible redox peaks at 1. 227 V/I. 772 V and 1. 334 V/1.761 V. Charge-discharge tests exhibit that the LisCr9Ti4024 material has good specific discharge capacity and rate capability at different rates. Charge-discharge curves at high rates show that LisCrgTi4024 material has high cycling stability. EIS patterns show that the solid electrolyte interphase （SEI） film on the surface of LisCr9Ti4024 material can be found after cycling.